As an intake apparatus configured to introduce an air for combustion into an engine for an outboard motor, there is an intake apparatus configured to introduce an exterior air through an engine cover (for example, refer to Patent Documents 1 and 2). In the intake apparatus, the exterior air introduced in the engine cover is delivered to an engine room. Then, the air flows in a space in the vicinity of an engine accommodated in the engine room and is then delivered to a combustion chamber. The exterior air introduced into the engine cover is warmed up during the flowing in the vicinity of the engine. For this reason, an engine output is lowered and a fuel consumption is deteriorated.
Therefore, as one of configurations for improving the fuel consumption of the outboard motor, there is proposed an intake apparatus which directly supplies the exterior air introduced from an exterior air introduction port of the engine cover to a throttle body without allowing the exterior air to flow in the space in the vicinity of the engine (for example, refer to Patent Document 3). According to this intake apparatus, since the exterior air is supplied to the throttle body without warming up the exterior air, it is possible to improve the engine output and the fuel consumption.
On the other hand, according to the above intake apparatus, a noise associated with the intake (an intake noise) is likely to occur and water such as ocean water is likely to enter into the engine. For this reason, it is important to suppress the intake noise and the entry of the water into the engine. According to the intake apparatus disclosed in Patent Document 3, an interference-type silencer is arranged on a flow path from the intake introduction port of the engine cover to the throttle body, thereby reducing the intake noise.    Patent Document 1: Japanese Patent Application Publication No. 2007-008416A    Patent Document 2: Japanese Patent Application Publication No. 2008-088881A    Patent Document 3: Japanese Patent Application Publication No. 2013-096342A
According to the intake apparatus disclosed in Patent Document 3, the exterior air introduced into the engine cover flows in an upper side area of the engine. The exterior air is supplied to the throttle body arranged at an upper side of the engine. For this reason, it is necessary to secure a predetermined space at the upper side of the engine in the engine cover. As a result, a size (particularly, a size in a vertical direction) of the intake apparatus is enlarged.
In addition, in the intake apparatus, the temperature of the introduced exterior air highly influences an intake packing efficiency of the engine. That is, it is known that an increase in the temperature of the introduced exterior air lowers the engine output and deteriorates the fuel consumption. For this reason, it is highly important to supply the introduced exterior air to the throttle body without increasing the temperature of the introduced exterior air, from a standpoint of improvements on the engine output and the fuel consumption.